Latent heat and specific heat

What is specific latent heat (L)?

• The amount of energy required to change the state of 1kg of the substance with a little temperature change.

• Is the energy transferred to 1kg of substance to raise its temperature by 1^oC.

• The amount of energy required to change the state of 1kg of the substance with no temperature change.

• The energy hiding in the substance.

This is the formula for latent heat of fusion:

• $Q=mC\Delta T+mL_f$

• $Q=mCA$

• $Q=mC\Delta T$

• $Q=mL_f$

Choose the correct symbol and unit for specific latent heat!

• L(kg/J

• L(J/kg)

• Q(J/kg^oC)

• W=P/T

What is the formula to find the amount of heat energy (Q) necessary when there's a phase change

• Q= (h)(ΔT)

• Q=(m)(L)

• Q=(m)(c)(ΔT)

• Q=(k)(A)(dT)

How do you calculate latent heat of vaporization?

• L_v = Q/m

• c = Q/(mΔƟ)

• Q = mcΔƟ

• Q = mL_v

What is the equation to measure change in Thermal Energy?

• Q=mC∆T

• Q=mC

• Q= ∆mCT

• C=Q/m∆T

The temperature is increasing in a glass of water. Describe the effect on its particles:

• Particles would slow down

• They would stop moving

• They would speed up

• There would be no effect

How do we calculate the heat energy released when 100 g of steam condenses.? Latent heat of vaporization = 2 300 000 J/Kg

• 100g x 2 300 000J/kg

• 10kg x 2 300 000J/kg

• 0.1kg x 2 300 000J/kg

• 0.1kg x 2 300 000J/kg x 100^oC

How much heat is needed to change 8 grams of ice at 0 ºC to 12 grams of water at 0ºC? L(heat of fusion) = 334 kJ/kg; C (specific heat capacity of water) = 4186 J/kg^oC

• Q = 8g x 4186 J/kg⁰C

• Q = 8g x 334kJ/kg

• Q = 8000kg x 334kJ/kg

• Q = 0.008 kg x 334kJ/kg

How much heat must be lost to change 110 grams of water at 0 ºC to 110 grams of ice at 0ºC? Heat of fusion = 334 kJ/kg; Specific heat of water = 4186 J/kg^oC

• Q = 110 x 4186

• Q = 110000 x 4186

• Q = 0.110 x 334

• Q = 110 x 334